Nowadays production can be done remotely to a much greater extent although the preference would I'm sure be to have most staff on site and in the Big Brother bubble so to speak.I think for them to be able to be live they will need a facility that will be able to be a production suite as well as a studio that can handle live crowds.
These days the investment of what they did in 2001 wouldn’t be able to be justified. Logically it would make sense that they go for somewhere that already has a fair bit of this capability to keep costs down. It also needs to be somewhere that is accessible for the e audience to attend.
Docklands Studios would make sense or even one of the other theme parks.
I remember back in 2006 that season alone to launch night cost upwards of $300million
I suspect they want somwhere which looks on TV to have a sizeable audience but is actually significantly smaller than Dreamworld, though I think C9 had already cut the crowd by about half in their era. Not sure how willing people would be to pay for tickets now.